Edge spring for upholstered furniture



0d, 6, 1964 w. F. RICHARDSON ETAL 3,151,853

EDGE SPRING FoR UPROLSTERED FURNITURE Filed Jan. 23, 1965 2 Sheets-Sheet l MM5", -z MMIII-iii, .Z0

SHE/2 Oct 6, 1964 w. F. RICHARDSON r-:TAL 3,151,853

EDGE SPRING FOR uPHoLsTERED FURNITURE Filed Jan. 23, 1963 2 Sheets-Sheet 2 United States Patent 3,151,853 E.D GE SPRING FOR UPHOLSTERED FURNITURE William F. Richardson and Raymond L. McQuitty, Carthage, Mo., assignors to Flex-O-Iiators, Inc., Carthage, Mo., a corporation of Missouri Filed Jan. '23, 1963, Ser. No. 253,418 S Claims. (Cl. 267-1) This invention relates to new and useful improvements 1n edge springs for upholstered furniture, and is an improvement over the edge spring shown in co-pending application Serial No. 211,686, iiled July 23, 1962, now abandoned.

T his invention relates to means for providing a cushion having a vertically yieldable formed edge, commonly known as a soft edge cushion, as distinguished from a hard edge cushion in which there are no spring supports but only rigid supports directly beneath the edge of the cushion. It is the prime object of the present invention to provide a soft edge cushion in a new and novel manner, by means which may be applied to ordinary hard edge spring decks without requiring alteration or modification of the latter. In the prior co-pending application referred to above, the object was accomplished by the provision of an elongated spring trough of generally V-shaped crosssectional contour adapted to be laid along the edge of a spring deck before the padding and upholstery layers are applied. One leg of the trough was aixed to the underlying frame and spring deck, while the other leg angled upwardly therefrom toward the edge of the cushion. Thus the open side of the trough was disposed directly above the edge of the frame, and the upper edge could be deected resiliently downwardly by a load applied thereto, since the trough was formed of a series of spaced spring wires bent in V-form and lying in planes normal to the axis of the channel.

The structure described above was generally satisfactory, but had one serious disadvantage in that if the trough were compressed severely, as by a person standing or otherwise exerting his full weight on the extreme edge of the cushion, the spring wires forming the trough were so severely stressed at the apex of the trough that they were permanently deformed or bent, causing the trough to be permanently collapsed. Not only did this tend to cancel the soft edge effect, but also the cushion edge became uneven and unsightly. The specific object of the present invention, therefore, is the improvement of the device to the end that it will not become permanently deformed or collapsed no matter how severely it is compressed. Generally, this object is accomplished by bending the sprung wires substantially double on themselves at the apex of the trough, and providing separation of the edges of the trough at the open side thereof by forming the upper leg of each wire with a relatively gentle curve. Thus when said upper leg is deflected downwardly, movement of the outer edge thereof is accomplished by a resilient curvature of said upper leg along its entire length, rather than by a sharp exure of the wires at the apex of the trough. The stress on the wire is thus distributed evenly along a much greater length thereof, and may be kept below the elastic limit of the wire, and the wires will not be deformed permanently even if the open edges of the trough are pressed into direct contact.

Other objects are simplicity and economy of construction, etiiciency and dependability of operation, and adaptability to be installed easily and conveniently in connection with general spring decks of many different types and constructions.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the accompanying drawings wherein:

FIG. l is a fragmentary top plan view of a furniture j 3,151,853 Patented Oct. 6, 1964 r"ice seating frame including a spring deck formed of sinuous wires, and with an edge spring embodying the present invention mounted thereon, the usual padding and upholstery layers being omitted,

FIG. 2 is an enlarged fragmentary sectional view taken on line II-II of FIG. 1,

FIG. 3 is an enlarged fragmentary sectional view of the upper edge portion of the spring trough, taken on line III-III of FIG. l,

FIG. 4 is an enlarged fragmentary sectional view of the apex portion of the spring trough, taken on line IV-IV of FIG. 1,

FIG. 5 is a fragmentary sectional View taken on line V-V of FIG. 2,

FIG. 6 is a View similar to FIG. 2, but with the padding and upholstery layers applied and with the spring trough compressed to the extent normally occurring when those layers are applied,

FIG. 7 is a view similar to FIG. 6 showing the spring trough fully compressed, and

FIG. 8 is a view similar to FIG. l, showing the edge spring fitted about a corner of the spring deck, and with the padding strip of the edge spring omitted.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies generally to a furniture frame which for example may be the seat frame of an upholstered chair, said frame being formed of Wood and including a front rail 4, side rails 6 and 8 rigidly attached to said front rail, and a back rail, not shown but parallel to front rail 4 and aixed to side rails 6 and 8.

Overlying frame 2 is a spring dack consisting of a series of sinuous spring wires 10 which are pre-formed to an upwardly bowed position as indicated in FIGS. 2, 6 and 7. The forward end of each wire 10 is engaged in a sheet metal clip 12 which is in turn fixed to the upper edge of front rail 4 by a pair of nails 14. Although not shown, it will be understood that the rearward ends of Wires 10 are similarly attached to the back rail of frame 2. This type of spring deck is only illustrative of the types of spring decks to which our edge spring may be applied, as it will become apparent that edge spring may be used generally with any spring deck the upper or load-supporting surface of which merges with the upper edge of the frame. An insulator pad, consisting usually of fabric or wire reinforced fabric, may be applied over the deck to better distribute the load and to prevent padding from sagging downwardly between wires 10. However, such insulator pad forms no part of the present invention, and is omitted from the drawing for purposes of clarity.

Assuming that rail 4 denes the forward edge of a furniture seat, it will be seen that when padding and upholstery layers are applied in the usual manner over the spring deck as thus far described, said rail will cause a relatively hard or unyielding sensation when a persons Weight is applied thereto, since while it may be covered with padding, there is no yielding spring support at this point. This hard edge engages the backs of the thighs of a person sitting on the seat, tends to restrict blood circulation in the legs, and is uncomfortable and objectionable. This hard edge effect is of course most noticeable when the spring deck within the open interior of frame 2 is exed downwardly by the weight of a person sitting thereon.

The elimination of this hard edge effect is accomplished by the provision of an edge spring indicated generally by the numeral 16, and consisting of an elongated trough-shaped member of resilient material and having a flared V-shape in cross-sectional contour, said member extending along the forward edge of the spring deck, or along any other edge thereof to which it is desired to impart the soft edge characteristic, and opening outwardly, the apex of the trough being secured to the spring deck, its lower edge being secured to frame 2, and its upper edge being disposed in spaced apart relation above its lower edge.

Specifically, thel edge spring is formed by a series of spring wires 18 bent in generally V-shape and arranged in spaced apart vertical planes normal to the axis of the trough, said wires being joined together by three cords 2t), 22 and 24 extending transversely to the planes of the wires. The cords are preferably formed of twisted paper or other soft but tough material, and each is provided with a spring wire core 26. Each wire 18, as best shown in FIG. 2, Yhas an upper leg 28 and a lower leg 30, connected by a substantially doubled bend 32 of the wire at the apex of the trough, best shown in FIG. 4. Approximately half the length of upper wire leg 28, extending from bend 32, is permanently formed in an upwardly concave curve, as indicated at 34, while the remaining or outer half of the length of the leg is normally straight, as indicated at 36. The outer ends of upper legs 28 of all of wires 18 are fastened to cord 20 by being wrapped tightly thereabout as indicated at 38 in FIG. 3, and the outer ends of lower legs 30 of all of wires 18 are fastened to cord 24 byA being wrapped tightly thereabout as indicated at 40, the compressibility of the cords providing that these connections will not slip. Each wire 18, at the bend 32 thereof, pierces cord 22 as best shown in FIG. 4, and bend 32 thereof is of such radius as to engage core wire 26 ofV said cord tightly therein. Cord 22 is firmly attached to the sinuous wires forming the spring deck, or to any convenient wires of other types of spring decks, by any suitable means such as clips 42. If an insulator pad has been applied over the spring deck as previously described, clips 42 also pierce said insulator pad. Cord 24 is secured to frame rail 4 by any suitable means such as staples 44. Cord may be further padded by a fiat padding strip 46 folded longitudinally around said cord, and secured by staples 48. Said padding strip may consist of several layers of soft pulp paper encased in a wrapper of relatively tough paper.

FIG. 2 shows ,the edge spring applied to the spring deck and frame, but in its normal, completely unrestrained position. In use, as shown in FIGS. 6 and 7, a layer of padding 58 of any desired type is applied over the spring deck and edge spring, Yand covered by one or more layers 52 of protective and decorative fabric or the like, the edges of the fabric being drawn down around the edges of frame 2 and secured to said frame under tension, as by tacking. FIG. 6 shows the edge spring compressed to the extent which generally occurs due to the application of the Vpadding and overlying fabric. FIG. 7 is the same except that it shows the edge spring substantially fully compressed, as would occur if a heavy, concentrated load were applied directly thereabove. In yielding from the FIG. 6 position to the FIG. 7 position, the edge spring provides the soft edge effect which is the prime objective of the invention. Y

In the edge spring shown in the prior co-pending application referred to above, the upper and lower legs 28 and 30 of each wire 18 were both straight, and the upper leg was restrained from iexing during compression of the spring by the load exerted by the padding thereon. As a result, flexure of the spring was heavily concentrated in the bend portion 32 of the wires, and caused an extreme concentration of stress at those points. Therefore, when the edge spring was heavily loaded, as in FIG. 7, the wires 18 were often deformed permanently at bends 32, causing the edge spring to be permanently collapsed, this not only Veliminated the soft edge effect at least to some extent,

but also caused the cushion to have an uneven, unsightly appearance.

The present improvement consists of forming the bend 32 of eachwire 18 as a substantially complete rebend or 180 degree bend, and providing separation or opening of the spring by inserting the upwardly concave curvature 34 in the upper leg 28 of each wire, said curvature extending for a substantial portion of the length of said leg. Since the wire is already bent double at 32, no foreseeable amount of pressure would bend it further, and it would not therefore be further stressed to any appreciable extent by any load exerted on the edge spring. Complete elimination of load stress at this point could be accomplished if bend 32 were completely closed so that the reaches of the wire at each side of the bend were in engagement with each other. However, the formation of such closed bends would cause breakage of the tempered spring steel wires, and the same result is obtained in any event by forming bends 32 to a permissably large radius into which the core wire 26 of cord 22 is snugly tted. Said core wire thus acts as a brace positively preventing any further yielding ofthe wire in the bend.

Thus the operative tlexure of the edge spring, in which cord 2G approaches cord 24, is accomplished not by yielding of the bends 32, but by general flexure of the upper legs 28 of wires 18 along their entire lengths, so that the stress of liexure is distributed through much longer portions of the wires, and is thereby kept well below the elastic limit of the wires, so that said wires are not permanently deformed even in extreme compression of the spring as in FIG. 7. Generally, this flexure of legs 28 is accomplished by a straightening of curved Vportions 34 thereof to a lesser curvature, as shown in FIG. 7. This straightening is not resisted or restricted, but is in fact aided, by the load exerted on the wires by padding 5t). The curves 34 of course could extend the full lengths of legs 28, but leaving the outer portions of said legs straight has certain advantages. If the legs were formed in a full length curve, then when the spring was fully compressed as in FIG. 7, the lowest or central portions of legs 28 would protrude downwardly between lower legs 30 of the wires. Such protrusion is often impossible with certain types of springs decks, or if the deck is covered by an insulator pad, and in any event would cause objectionable grinding and rattling noises by contact of the upper and lower legs. With the half-length curves 34 as shown, flexure of the spring is accomplished by straightening of the Vcurved portions 34, and a reverse or upwardly convex curvature of the normally straight portions 36, so that as the spring is compressed each leg 28 assumes a gentle S-configuration as shown in FIG. 7. This S-curvature provides that in an edge spring of given strength, legs 28 will be much more nearly straight when fully deiiected than would be possible if said legs were originally formed with a full-length curvature, so that legs 28 need never contact or extend between the lower legs 3i). The legs 28, being straighter, also provide a better support for the padding disposed thereover.

FIG. 8 shows the edge spring as described above bent to encompass the corner of a spring deck and furniture frame, with padding strip 46 omitted. In making such an application, the cords 20 and 24 are curved about radii nearly enough equal to avoid interference.therebetween. However, the cord 22 would normally be excessive in length in the corner, so as to gather or bunch up objectionably. To prevent this, cord 22 may be cut into short lengths S4 in the portion thereof in the bend, the cuts being made between wires 18. These short lengths may overlap each other freely as shown, to avoid bunching of the cord and to prevent objectionable disarrangement of the associated wires 18. The short cut lengths 54 of the .cord could be removed, but are preferably left in place What we claim as new and desire to protect by Letters Patent is:

1. An edge spring for upholstered furniture comprising a trough-shaped member of generally V-shaped crosssectional contour having divergent legs, and being formed of resilient material whereby said legs may be exed yieldably toward each other, said resilient material being folded substantially double on itself along the apex of said trough shape, one of said legs being substantially planar and the other of said legs being concavely curved at the side thereof distal from said first leg, said troughshaped member comprising:

(a) a series of spring Wires each formed to the crosssectional contour of said member, said wires being disposed in parallel, spaced apart planes normal to the longitudinal extent of said member, and

(b) a plurality of elongated strands extending longitudinally of said trough and each secured to each of said wires at its point of intersection therewith.

2. An edge spring as recited in claim l wherein one of said strands intersects each of said Wires at the bend thereof dening the apex of said trough-shaped member, and with the addition of:

(a) an incompressible member carried by s-aid strand and extending coextensively therewith, said last @Ei named member being engaged snugly in said bend of each of said wires, to prevent yielding of the wire portions incorporated in said bends.

3. An edge spring as recited in claim l wherein one of said strands intersects each of said Wires at the bend thereof defining the apex of said trough-shaped member, said strand constituting a spring wire core having a covering of relatively soft material, each of said wires piercing said covering with said bend thereof snugly engaged about said core wire.

4. An edge spring as dened in claim 1 wherein the curvature of said curved leg extends from said fold only a portion of the length of said leg, the free edge portion of said curved leg being substantially planar.

5. An edge spring as defined in claim 1 wherein the curvature of said curved leg extends from said fold for approximately one-half of the length of said leg, the other one-half of said leg being substantially planar.

References Cited in the le of this patent UNITED STATES PATENTS 

1. AN EDGE SPRING FOR UPHOLSTERED FURNITURE COMPRISING A TROUGH-SHAPED MEMBER OF GENERALLY V-SHAPED CROSSSECTIONAL CONTOUR HAVING DIVERGENT LEGS, AND BEING FORMED OF RESILIENT MATERIAL WHEREBY SAID LEGS MAY BE FLEXED YIELDABLY TOWARD EACH OTHER, SAID RESILIENT MATERIAL BEING FOLDED SUBSTANTIALLY DOUBLE ON ITSELF ALONG THE APEX OF SAID TROUGH SHAPE, ONE OF SAID LEGS BEING SUBSTANTIALLY PLANAR AND THE OTHER OF SAID LEGS BEING CONCAVELY CURVED AT THE SIDE THEREOF DISTAL FROM SAID FIRST LEG, SAID TROUGHSHAPED MEMBER COMPRISING: (A) A SERIES OF SPRING WIRES EACH FORMED TO THE CROSSSECTIONAL CONTOUR OF SAID MEMBER, SAID WIRES BEING DISPOSED IN PARALLEL, SPACED APART PLANES NORMAL TO THE LONGITUDINAL EXTENT OF SAID MEMBER, AND (B) A PLURALITY OF ELONGATED STRANDS EXTENDING LONGITUDINALLY OF SAID TROUGH AND EACH SECURED TO EACH OF SAID WIRES AT ITS POINT OF INTERSECTION THEREWITH. 